The sodium concentration in the central nervous system may play an important role in cardiovascular function and body fluid regulation. The purpose of this investigation was to examine the effects of intracerebroventricular ICV infusion of hypertonic NaCl solutions on the cardiovascular responses in normotensive and 2-kidney, 1 clip 2K1C renal hypertensive rats. Methods 2K1C hypertension was made by clipping the left renal artery and were used 4 weeks later. Age-matched control rats received a

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... ham treatment. Under thiopental 50 mg kg, IP anesthesia, both isotonic and hypertonic NaCl solutions 0.15 M, 0.6 M and 1.2 M were ICV applied, while blood pressure and heart rate HR responses were continuously monitored. Results Central administration of hypertonic NaCl solution caused an elevation in mean arterial pressure MAP and HR in both normotensive and 2K1C hypertensive rats. The response magnitude in the blood pressure was positively correlated to the NaCl concentration in normotensive rats, while the pressor responses to hypertonic NaCl were comparable regardless of the concentration of NaCl in hypertensive rats. Despite of the HR responses were similar in between two groups, the magnitude of the MAP increases were more elevated in hypertensive than in normotensive control rats. Isotonic NaCl solution, when centrally applied, caused an elevation in blood pressure only in hypertensive rats. Conclusion These results indicate that the central sensitivity to sodium chloride is altered in 2K1C renal hypertensive rats. Korean Circulation J 1999 ; 29 2 : 216-221 KEY WORDS Hypertonic NaCl·Intracerebroventricular·Cardiovascular·Renal hypertension. 서 론